If “smoking” e-cigarettes is your thing, you may need to use more sick days at work.

A new study shows that e-cigarette vapor causes inflammation in young, healthy airway cells. Scientists from National Jewish Health in Denver used cells from young organ donors and exposed them to the vapor using a machine to simulate “vaping.”

After as little as 10 minutes, the cells showed signs of inflammation.

And, it didn’t seem to matter whether the e-cigarette liquid used in the experiment contained nicotine or not. Both types of the liquid produced similar results.

The researchers also exposed the cells to human rhinovirus, better known as the common cold, and checked on them six hours and 24 hours later. The cells contained higher levels of the virus than other cell samples not subjected to e-cigarette vapor.

Put together, these two effects… increased inflammation and higher amount of viruses… mean that using e-cigarettes likely increases a person’s risk of coming down with a respiratory illness.

In case you’re wondering, scientists say traditional cigarettes cause similar problems.

The negative effects of e-cigarettes uncovered in this study are certainly not the first to be identified. For one, there’s the chance that e-cig users will become hooked on nicotine and look to other sources to get their fix.

Other substances used to make e-cigarette liquid are questionable, too. In 2009, the U.S. Food and Drug Administration announced that the liquid contains carcinogens and toxic chemicals, including one used in antifreeze.

The Centers for Disease Control and Prevention also says there’s no evidence that using e-cigarettes helps people quit smoking cigarettes, as some supporters say it does.

Smokers and vapers alike: If you want to kick the habit, visit smokefree.gov for tips to help you become nicotine-free.